Thermosensitive circuit controller



1,629,710 May 24 1927' P. E. KLoPsTEG ET AL THERMOSENSITIVE CIRCUIT CONTROLLER Filed May 20, 1922 l figa `Patented May 24, 1927.

UNITED STATES 1,629,710 PATENT OFFICE.

PAUL E. KLOIPSTEG, OF CHICAGO, AND WINFIELD H. STANNARD, OF HOMEWOOD, ILLI- NOIS, ASSIGNORS T CENTRAL SCIENTIFIC COMPANY, 0F CHICAGO, ILLINOIS, A

CORPORATION OF ILLINOIS.

THERMOSENSITIVE CIRCUIT C0NTROLI'JLEIR'.

Application filed May 20,

This invention relates to a thermosensitive circuit controller and has for its object broadly to improve the device disclosed in Patent No. 1,375,780 granted to A. De Khotinsky, April 26, 1921.

' An important object of the invention is to equip such a controller with an easily readable scale or the like that will permit sett-ings of the controller to be accurately made and read.

A further object of the invention is to so mount the contacts as to give them a wiping action.

Further objects of the invention will become apparent as the description is read in connection with the accompanying drawing showing a selected embodiment of the invention in which- Fig. 1 is a side elevation showing a device with a casingl or cover thereon;

Fig. 2 isalongitudinal section illustrating the operating mechanism;

Fig.'3 is a figuresimilar to Fig. 1 with the cover orl casing removed;

Fig. 4 is an enlarged detail shown in section on the line 4-4 of Fig. 3;

Fig. 5 is a longitudinal section on the line 5 -5 of Fig. 3;

Fig. 6 is a side elevation of one form of D movable contact; and

Fig. 7 is a side elevation of a modified form.

Referring to the drawings 10 indicates a base which mayV be of any suitable material but which we prefer to make oi some form of insulator. Attached to this base near one end and at the side is an upright 11 which carries a pair of binding posts 12 electrically connected with a pair of fixed contacts 13. Upright 11 is preferablyy of insulating material so that whenever desired the circuit can be brought in at one of the binding posts 12 and out at the other binding post 12. The contacts 13 make and break the circuit by engagement with similar contacts 14 carried by a movable arm 15 shown in detail in Fig. 6. As illust-rated in Fig. 3 this arm may be connected by a short cable 16 with a binding post 17 carried by a second upright 18 supported on the base. In some cases it will be desirablevto use the double contacts 13-14 for attach-.J

ment to one side of a line connected to a 1922. Serial No. 562,438.

source of electric current and under such circumstances the cable 16 and the binding post 17 may be used forthe other side of the same line.

One important application of this invention is in connection with ovens and we have shown a sleeve 19 connected with the base 10 and extending a suiiicient distance to pass through a wall or walls of t-he oven. In the present illustration the base is provided with a socket 20 receiving an internally threaded end 21 of the sleeve secured thereto by the nut 22. Rotatably mounted 'within the sleeve 19 is a tube 23 carrying at its outer end a collar 24 to which one end of a bimetallic coil 25 is secured by a screw 26. The other end of the coil 25 is secured to a rod 27 freely passingthrough the tube 23 and carrying at its opposite end the movable arm 15 which is adustably rsecured' thereto by a screw 28. In the normal operation of the device the tube 23 is set in a temporarily fixed position depending upon the temperature at which it is desired to have the contacts 13 and 14 open or close and the thermosensitive element 25 rotates the rod 27 when the temperature reaches the proper point thereby swinging the movable arm 15 and opening or closing the contacts.

The upper end of the tube 23 in Fig. 2 is equipped with a worm wheel 29 suitably secured thereto and incidently forming a bearing for the rod 27. The worm wheel 29 meshes with the worm 30 so that the tube 23 may be rotated to adjust the temperature at which the circuit will be opened or ,closed by the action of the bimetallic coil. Preferably this worm 30 is swivelled in a block 31 which is pivoted to the casing by screw 32 and normally held in position to engage the worm wheel by the spring 33. The block 31 is cut away at 34 to make room lfor a section of a nut 35 engaging the worm and connected to a sliding scale 36 by screw 37. This causes the scale 36 to move by an index mark 38 when the worm is turned to adjust for diierent temperatures. This scale might be fixed and the index markv movable but in the particular construction, lack of space makes it more convenient to have the scale move.' The worm is preferably provided with a head 39 which is graduated at 40 to indicate smaller readings than the scale 36. The graduations on these two scales may be varied to suit particular conditions. It is preferable to have the smallest divisions on the scale 36 correspond to one complete rotation of the worm and to divide the circumference of the head 39 intofa suitable number of divisions to indicate the smallest fraction that will be required in the particular use. The head' 39 is preferably provided with a suitable knob 41 by which the worm is turned and the adjustments made. The casing 42, which covers everything on the upper side of the base except the head 39 and the knob 41, is held in place by suitable screws 43 passing through slots in the walls of the casing. Preferably the uprights 11 and 18 are provided with projections carrying the binding posts 12 and 17 that extend just beyond the outer edge of the casing. A window 44 is provided in the top of the casing to permit the scale 36 to be readily read, and the end of the casing adjacentl thereto bears an index mark 45 for use in conjunction with the scale 40. Preferably we also provide the top of the casing with a suitable space S46 on which the owner of a particular instrument can place his calibration marks. These marks may be of any particular character and will vary according to the particular graduations on the scales 36 and 39.

Preferably, the contacts 14 are carried by the light spring 47 which is split at 48 between the contacts and normally tends to swing them slightly downward from the movable arm 15 as it is illustrated in Fig. 3. The object of this mounting is to cause the contacts to have a wiping action.

From the foregoing it will be seen that we -have equipped the thermosensitive controller of the Khotinsky patent with improved contacts and with a very convenient scale that will permit accurate settings of the instrument and will also enable accurate v readings to be taken therefrom.

The presence of the contacts 13 and 14 and the cable 16 makes it possible to pass the current through the controller in different ways and to suit different conditions.

The particular mounting of the block 31 which carries the worm permits ready engagement or disengagement of the worm in the worm wheel, which is very advantageous both in the assembly of the instrument and in its use. By having the scale 36 move and the index remain stationary, it is possible even in this small instrument to provide adequate window space 44 and sufficient space 46 to carry the calibration figures necessary to make the settings of themstrument particularly accurate. I

The arrangement. of the scale 40 with its index 45, the scale 36 with its index 38 and the calibration space 46 all in a little group substantially in line makes it possible to quickly and easily adjust the setting of the machine or check the setting when it has been made by a subordinate.

In Fig. 7 we have illustrated a modified construction that is especially adapted for use where very accurate temperature control is desired. The fixed contacts 13 are replaced by rotating contacts in the form of disks 50 which may be mounted on a fibre shaft 51 and driven in any suitable manner. In most 'applications there will be some source of power that can be conveniently arranged to rotate the shaft 51 at a suitable speed. The disks 50 may be connected with binding posts 52 in a variety of ways, of which the brushes 53 will serve as an illustration. The axis of the disks 50 is fixed and, when the disks are circular which is the preferable construction, they may still be considered as fixed contacts, for the position of the contacting portion of their peripheries is fixed. y

The action of the bi-metallic coil 25 is necessarily somewhat sluggish and, for that reason, there is a tendency for the contacts to arc. in the initial separation. This results in sufficient sticking to permit the temperature to rise above the desired constant before the current is entirely cut off. By the use of the rotating contacts this arcing and sticking is almost entirely eliminated and the line of temperature is practically as straight as can be drawn with a ruler.

This construction also has the additional advantage that approximately twice the current can be used as compared with the point contacts 13.

We are aware that changes may be made in the form, construction and arrangement of the invention, asset forth in the selected embodiments herein, without departing from the scope or sacrificing any of its material advantages, and we therefore reserve the right to make all such changes as fairly fall within the scope of the following claims.

We claim:

1. A thermosensitive current controller comprising a fixed contact, a movable contact, thermosensitive means connected to said movable contact, a scale movable independently of said thermosensitive means, and means to adjust saidthermosensitive means and connected to said scale whereby said scale will move with said adjusting means the movement of the scale bein dependent solely upon the movement o the adjusting means and not upon the movement of said thermosensitive means. Y

2. A thermosensitive current controller comprising a fixed contact, a. movable contact, thermosensitive means connected to said movable cont-act, indicating means operable independently of said thermosensitive ele.

said indicating means whereby adjustment of said thermosensitive means Will operate said indicating means the movement of the indicating means being dependent upon the movement of the adjusting means and not upon the movement of said thermosensitive l means.

3. A thermosensitive current controller comprising a fixed Contact, a movable contact, a thermosensitive means connected to said movable contact, a Worm gear connected to said thermosensitive means, a Worm meshing with. said Worm gear', means to rotate said Worm and indicating means operated by rot-ation of said Worm, said indicating means being in its movement` dependent upon the movement of said adjusting means and not upon that of said thermosensitive means.

4. A thermosensitive current controller comprising a lixed contact, a movable contact, thermosensitive means connected to said movablel contact, a Worm gear connected to said thermosensitive means, a Worm for operating said Worm gear, a pivoted block in which said Worm is swiveled, a nut threaded on said worm, and indicating means carried by said nut, whereby rotation of said Worm to adjust said thermosensitive element will cause movement of said nut and said indicating means.

5.1A thermosensitive current controller' comprising a fixed contact, a movable contact, thermosensitive means connected to said movable Contact, a Worm gear connected to said thermosensitive means. a Worm for operating said Worm gear, a pivoted block in which said Worm is swiveled, a nut threaded on said Worm, indicating means carried by said nut, whereby rotation of said Worm to adjust said thermosensitive element will cause movement of said nut and said indicating means, a head on said Worm, and indicating means carried by said head and bearingA a fixed relation to said first named indicating means.

6. A. thermosensitive currentcontroller comprising a plurality of fixed contacts, a movable arm' having a plurality of contacts corresponding in number to the fixed contacts and adapted to engage said fixed contacts simultaneously, a thermosensitive element controlling the movement of said arm, a rotatable member operatively connected with said element and with said arm, and means to adj ust said thermosensitive element said means comprising a member in driving engagement therewith, and a pivoted member in which said first-named member is swiveled. l

7. A thermosensitive current controller comprising a thermosensitive element, an arm controlled by said thermosensitive element, a contact on said arm, and a rotatable contact member adapted to engage with said first named contact and a brush cooperating with said rotatable 'Contact'.

PAUL E. KLOPSTEG. WINFIELD H. STANNARD. 

